Three metallic wires of identical composition are supplied in the laboratory. Answer the following questions about them.
(i) Define electrical resistance and list four factors on which the resistance of a uniform metallic wire depends.
(ii) For each factor named in part (i), explain qualitatively how an increase in that factor affects the resistance of the wire, keeping all other factors constant.
(iii) The three wires have the following dimensions:
Wire A : length 20 cm, diameter 0.50 mm
Wire B : length 40 cm, diameter 1.00 mm
Wire C : length 10 cm, diameter 0.25 mm
All three are at the same temperature and made of the same material. Arrange the wires in decreasing order of their resistances and justify your answer with proper reasoning based on their dimensions.